Projection system with integrated optical device

Abstract

An integrated prism-based optical device for a projection system performs light integration, beam shaping, and input/output beam separation. The integrated optical device preferably includes a light integrator tunnel with a first lens located adjacent one end and a prism located adjacent an opposite end. A second lens is located adjacent another side. The individual elements are preferably secured together using an index matching adhesive to form a unitary optical device. The integrated optical device is compact and provides uniform, high intensity light to the display device. The integrator tunnel may have a wedge or frustum shape eliminating the need for the first lens. The integrated optical device allows for a projector that requires fewer parts, is lighter weight, more compact, less costly, and more easily assembled than prior projection systems.

What is claimed is:  
     
       1. An integrated optical device for use in an image projection system that includes a light source for emitting a light beam that propagates along an optical path through the integrated optical device and is received by a display device that produces a color image, comprising: 
       a light integrating tunnel having an input end and an output end; and  
       a prism component having first and second sides, the first side secured to the output end of the light integrating tunnel with an adhesive so that the light beam propagates directly from the output end of the light integrating tunnel to the prism component.  
     
     
       2. The integrated optical device of  claim 1  in which the light integrating tunnel and the prism component are made of glass having a refractive index, wherein the adhesive has a refractive index that substantially matches that of the light integrating tunnel and prism component. 
     
     
       3. The integrated optical device of  claim 1  in which the light integrating tunnel is elongated and has a substantially constant cross section along its length so that the input end and the output end have substantially the same dimensions. 
     
     
       4. The integrated optical device of  claim 1  further comprising a lens element abutting the input end of the light integrating tunnel. 
     
     
       5. The integrated optical device of  claim 1  further comprising a first lens element adhesively secured to the input end of the light integrating tunnel and a second lens adhesively secured to the second side of the prism component. 
     
     
       6. The integrated optical device of  claim 5  in which the adhesive used to secure the first lens to the light integrating tunnel and the second lens to the prism component is an index matching adhesive. 
     
     
       7. The integrated optical device of  claim 1  in which the light integrating tunnel has a substantially frustum shape in which the input end has a smaller cross section than the output end. 
     
     
       8. The integrated optical device of  claim 7  further comprising a lens element abutting to the second side of the prism component. 
     
     
       9. The integrated optical device of  claim 8  in which the lens element is secured to the second side of the prism component with an index matching adhesive. 
     
     
       10. An integrated optical device for use in an image projection system that includes a light source for emitting a light beam that propagates along an optical path through the integrated optical device and is received by a display device that produces a color image, comprising: 
       a light integrating tunnel having an input end and an output end;  
       a first lens element adhesively secured to the input end of the light integrating tunnel;  
       a prism component having first and second sides, the first side abutting the output end of the light integrating tunnel so that the light beam propagates directly form the output end of the light integrating tunnel to the prism component; and  
       a second lens adhesively secure to the second side of the prism component.  
     
     
       11. The integrated optical device of  claim 10  in which the light integrating tunnel and the prism component are secured together with an adhesive. 
     
     
       12. The integrated optical device of  claim 11  in which the light integrating tunnel and the prism component are made of glass having a refractive index, wherein the adhesive has a refractive index that substantially matches that of the light integrating tunnel and prism component. 
     
     
       13. The integrated optical device of  claim 10  in which the light integrating tunnel is elongated and has substantially constant cross section along its length so that the input end and the output end have substantially the same dimensions. 
     
     
       14. The integrated optical device of  claim 10  in which the adhesive used to secure the first lens to the light integrating tunnel and the second lens to the prism component is an index matching adhesive. 
     
     
       15. The integrated optical device of  claim 10  in which the light integrating tunnel has a substantially frustum shape in which the input end has a smaller cross section than the output end. 
     
     
       16. An integrated optical device for use in an image projection system that includes a light source for emitting a light beam that propagates along an optical path through the integrated optical device and is received by a display device that produces a color image, comprising: 
       a light integrating tunnel having a substantially frustum shape, an input end, and an output end, the input end having a smaller cross section than the output end;  
       a prism component having first and second sides, the first side abutting the output end of the light integrating tunnel so that the light beam propagates directly from the output end of the light integrating tunnel to the prism component; and  
       a lens element abutting to the second side of the prism component.  
     
     
       17. The integrated optical device of  claim 16  in which the light integrating tunnel and the prism component are secured together with an adhesive. 
     
     
       18. The integrated optical device of  claim 17  in which the light integrating tunnel and the prism component are made of glass having a refractive index, wherein the adhesive has a refractive index that substantially matches that of the light integrating tunnel and prism component. 
     
     
       19. The integrated optical device of  claim 16  further comprising a lens element abutting the input end of the light integrating tunnel. 
     
     
       20. The integrated optical device of  claim 19  in which the adhesive used to secure the first lens to the light integrating tunnel and the second lens to the prism component is an index matching adhesive.